• 환경생물
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• 제29권3호
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• pp.113-125
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• 2011

Seabirds have adapted to life in marine environments. More than 25% of the bird species observed in South Korea are seabirds, using the coast area of Korean peninsula as a stop-over and wintering, and breeding site. The aims of this review are to provide information about migratory and resident Korean seabirds and to discuss the methods that are currently employed to monitor the marine environment. In Korea, it has been reported that more than 400,000 individuals of seabirds breed on Nando Islet, Chilbaldo Islet, Guguldo Islet, Sasudo Islet, Hongdo Islet and Dokdo Islet. In 2010, approximately 160,000 seabirds also visited South Korea during the winter. Two of the main treats were introduced wildlife and habitat destruction by humans. Seabirds are monitored mainly at the population and individual levels. The assessment of population sizes and biomagnifications of pollutants are performed preferably at the community and population levels. Behaviour, growth, morphological characteristics, and breeding success is analyzed at the individual level and employed to gauge the health of the marine environment. In addition, we could suggest that molecular technique of seabirds successfully adopted to investigate the effects of pollutants and toxins in the marine environment.

• The Korean Journal of Ecology
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• 제18권3호
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• pp.397-408
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• 1995

This study was conducted to analyze the breeding bird community by using guild concept in Mt. Baekwoon Research Forest of Seoul National University. Bird Community was studied by line transect method during the breeding seasons of birds in 1982 and its results were compared and analyzed with the Park et al. Work in 1993. Guilds were characterized by nesting and foraging sites as follows: nesting guild - (H) hole, (C) canopy, (B) bush, (E) edge; and foraging guild - (o) outside, (c) canopy, (b) bush. Bush-nesting guilds such as Tricolor Flycatcher (Ficedula zanthopygia), Blue-and-White Flycatcher (Cyanoptila cyanomelana), Stonechat (Saxicola torquata), Bush Warbler (cettia diphone) and Skylark (Alauda arvensis) had disappeared after ten years. Outside-foraging guilds such as Common Buzzard (Buteo buteo), sparrow Hawk (Accipiter nisus) and Carrion Crow (Corvus corone) also were not observed. There was a sharp decrease of species richness of bush-nesting guild, canopy-foraging guild and bush-foraging guild compared to ten years ago. These decreases indicate that forest environment of this area has been changed for the ten years, and guild concept in this study can be used usefully to elucidate the change of bird community according to the change in forest environment.

• 농업과학연구
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• 제48권3호
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• pp.465-471
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• 2021

Grass breeding starts with the process of selecting grass with good traits, and this operation consumes a lot of resources. Therefore, there is a need for an efficient screening method. Stolon is a unit for the storage of carbohydrates and vegetative propagation, which enhances grass growth and grass sod. Grass varieties with active production of stolons have excellent traits because they reproduce quickly and have a high density. To select grass with such a trait, the survival rate and the production rate of stolon after transplantation of 72 grass germplasms were investigated. After transplantation, the survival rate ranged from 75% to 100%. The majority of the grass cultivars showed a 100% survival rate. Therefore, the group was divided into two groups: A grass variety showing 100% survival and a grass variety that did not show 100% survival. The grass cultivar group, which showed a 100% survival rate after transplantation, included 61 turf varieties, and the rates of stolon production in these grass varieties ranged from 0 to 100%. In contrast, 10 varieties were included in the grass cultivar group that did not show 100% survival after transplantation. These cultivars had a stolon production rate of 0 to 33%. The results suggest that grass germplasms with a 100% survival rate should be selected.

• 한국환경복원기술학회지
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• 제23권4호
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• pp.97-110
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• 2020

This study conducted observations at 72 traffic lights and road signs in Sejong-si, Korea from March to June 2019 in order to analyze nest-site, nest-site characteristics and feeding behavior in Tree sparrow (Passeer montanus) in urban. Feeding behavior during breeding season in 2019 was investigated at 10 Town representing traffic facilities installed on the road located in the center of the city and 10 Riverside Geumgang river's riverside road. We fitted both general linear model and regression model to our field data and estimated the spatial variation of initial date of the first feeding (i.e., being date of breeding) and the total number of caterpillar fed by parents per hour. Our results showed that the frequency of nest building on artificial structures, such as traffic lights, was about 26% higher and about 8 days earlier in the riverside. In particular, the first feeding was significantly faster when the nearest distance between nest to green field as foraging site was shorter whereas there was no significant effect of the number of nest within 50 meters on the first feeding. Number of caterpillars fed by parents was higher in the Riverside than in the Urban, and especially the number in the second brood was sharply decreased in the Urban. As we estimated average amount of caterpillars per hour to 446 traffic safety facilities in Sejong-si, it was estimated that Tree sparrows fed 18,742.8 caterpillars per hour during the breeding season. In this study, we showed that characteristics of nests built in artificial structures and feeding behavior in order to analyze effects of environmental condition in urban on life-history traits during the breeding season. Finally, we discussed the conservation of birds in urban and pest control effects.

• 한국환경생태학회지
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• 제22권5호
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• pp.595-597
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• 2008

경기도 이천에서 3개의 알을 산란하여 포란 중인 수리부엉이 둥지를 촬영하였다. 2개의 알에서 새끼가 부화하였으나 1마리는 사라졌고, 2007년 3월 8일 남은 1마리가 사망한 후 어미는 죽은 새끼를 먹었으며, 이튿날 어미는 번식을 포기하고 둥지를 떠났다.

• Journal of Ecology and Environment
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• 제34권4호
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• pp.357-363
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• 2011

To examine factors affecting feeding efficiency of grey herons (Ardea cinerea), the foraging behavior was studied at a reservoir in Asan city, Chungcheongnam-do, South Korea during the breeding seasons (from April to July) of 2006 and 2007. Four factors (age of foraging birds, time of day, breeding stage, and microhabitat type) were analyzed. Adults were more efficient foragers than recently fledged juveniles, and they had a higher success rate than juveniles. About half of the adults caught large prey, whereas most juveniles caught only small prey. Adult grey herons had different feeding efficiency according to the breeding stage. Pecking and capture rates were high during the late period (fledging stage), and biomass intake rates were high during the early (incubating stage) and late periods. However, time of day had no significant effect on foraging activity of adult grey herons. Feeding activities of adult grey herons also showed significant variation among microhabitat types. Pecking and capture rates were higher in the submerged plants area, but capture success rate and biomass intake rate were not different according to microhabitat type.

• Journal of Ecology and Environment
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• 제29권1호
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• pp.35-39
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• 2006

During the breeding seasons in 2002 and 2003, the influences of vegetation cover on breeding processes of Black-tailed Gulls (Laurs crassirostris) were studied on Hongdo Island. We checked dutch sizes, calculated hatching success and survival rates on day 15 and a vegetation cover, There was significant positive relationship between vegetation cover and hatching success, and survival on day 15. In order to analyze the relationship, sample nests were categorized as 'exposed' and 'covered' nests, and the breeding processes at each nest were compared. Hatching success and survival on day 15 in covered nests were significantly higher than ones in exposed nests. However, in clutch size, there was no significant difference. The rate of the hatching and survival failure was different amongst the categorized nests. The primary cause of hatching failure in covered and exposed nests was 'disappeared', and the primary causes of survival failure on day 15 were 'disappeared' and 'killed by adults'. The failure in exposed nests was significantly larger than that of covered nests. In the breeding of Black-tailed Gulls on Hongdo Island, vegetation cover influenced the survival of eggs and chicks as the cover provided shelter against predators and extreme weather.

• Animal Bioscience
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• 제35권11호
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• pp.1635-1648
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• 2022

Thermal stress due to extreme changes in the thermal environment is a critical issue in cattle production. Many previous findings have shown a decrease in feed intake, milk yield, growth rate, and reproductive efficiency of cattle when subjected to thermal stress. Therefore, selecting thermo-tolerant animals is the primary goal of the efficiency of breeding programs to reduce those adverse impacts. The recent advances in molecular genetics have provided significant breeding advantages that allow the identification of molecular markers in both beef and dairy cattle breeding, including marker-assisted selection (MAS) as a tool in selecting superior thermo-tolerant animals. Single-nucleotide polymorphisms (SNPs), which can be detected by DNA sequencing, are desirable DNA markers for MAS due to their abundance in the genome's coding and non-coding regions. Many SNPs in some genes (e.g., HSP70, HSP90, HSF1, EIF2AK4, HSBP1, HSPB8, HSPB7, MYO1A, and ATP1A1) in various breeds of cattle have been analyzed to play key roles in many cellular activities during thermal stress and protecting cells against stress, making them potential candidate genes for molecular markers of thermotolerance. This review highlights the associations of SNPs within these genes with thermotolerance traits (e.g., blood biochemistry and physiological responses) and suggests their potential use as MAS in thermotolerant cattle breeding.

• Asian-Australasian Journal of Animal Sciences
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• 제20권1호
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• pp.12-18
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• 2007

The objective of the study was to compare ranking of Sahiwal bulls selected on the basis of highest lactation milk yield of their dams with their estimated breeding values (EBVs) using an animal model. Data on 23,761 lactation milk yield records of 5,936 cows from five main Livestock Experiment Stations in Punjab province of Pakistan (1964-2004) were used for the study. At present the young A.I bulls are required to be from A-category bull-dams. Dams were categorized as A, B, C and D if they had highest lactation milk yield of ${\geq}$2,700, 2,250-2,699, 1,800-2,249 and <1,800 litres, respectively. The EBVs for lactation milk yield were estimated for all the animals using an individual animal model having fixed effect of herd-year and season of calving and random effect of animal. Fixed effect of parity and random effect of permanent environment were incorporated when multiple lactation were used. There were 396 young bulls used for semen collection and A.I during 1973-2004. However, progeny with lactation yields recorded, were available only for 91 bulls and dams could be traced for only 63 bulls. Overall lactation milk yield averaged 1,440.8 kg. Milk yield was 10% heritable with repeatability of 39%. Ranking bulls on highest lactation milk yield of their dams, the in-vogue criteria of selecting bulls, had a rank correlation of 0.167 (p<0.190) with ranking based on EBVs from animal model analysis. Bulls' EBVs for all lactations had rank correlation of 0.716 (p<0.001) with EBVs based on first lactation milk yield and 0.766 (p<0.001) with average EBVs of dam and sire (pedigree index). Ranking of bulls on highest lactation yield of their dams has no association with their ranking based on animal model evaluation. Young Sahiwal bulls should be selected on the basis of pedigree index instead of highest lactation yield of dams. This can help improve the genetic potential of the breed accruing to conservation and development efforts.

• 생태와환경
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• 제51권2호
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• pp.168-173
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• 2018

멸종위기야생생물 (II급)임과 동시에 천연기념물(제453호)로 지정되어 있는 남생이(Mauremys reevesii)는 서식지파괴, 환경오염, 불법 포획 등의 원인으로 매우 빠르게 감소하고 있는 토종 파충류이다. 하지만 적은 개체수와 개체확보의 어려움, 연구의 부족은 남생이의 효과적인 관리를 저해하는 요소가 된다. 본 연구에서는 국립공원연구원에서 관리중인 남생이 유체 7개체를 대상으로 개별 먹이 급여가 개체에 미치는 영향을 파악하였다. 연구 결과, 개별 사육 및 먹이 급여는 각 개체의 특성을 고려한 먹이 급여를 가능하게 하였다. 또한 모든 개체의 체중과 등껍질 길이에서 뚜렷한 성장과 발달이 나타났으며, 이는 연구 전 통합사육에서 나타났던 개체 간에 크기 차이를 줄이는데 영향을 주었다. 게다가 동면기인 겨울철 인위적인 사육은 개체들의 성장, 행동, 외부형태에서의 가시적인 문제를 일으키지 않았다. 이러한 개별 사육은 남생이 유체들의 효과적인 성장과 발달을 유도할 수 있으며, 야생으로 방생할 때 생존율을 높이는 방안이 될 것이다.